In an electronic device, a sealing material is used so as to protect electronic components, such as a semiconductor element, from an external environment, such as shock, pressure, humidity and heat. As an example of the sealing material, an epoxy, phenol-based sealing material containing an epoxy resin as a base resin and a phenol resin as a hardening agent has been generally used.
In recent years, a semiconductor substrate of electronic devices has been shifted from a Si substrate to a SiC substrate having higher performance. The electronic device having the SiC substrate is assumed to be used in a high temperature environment, such as 200 to 250 degrees Celsius (° C.). On the other hand, the heat-resistant temperature of the epoxy, phenol-based sealing material is from 150 to 200° C. Therefore, development of a sealing material having a higher heat-resistant temperature has been required.
As a material having excellent heat resistance, a heat resistant resin composition that contains a maleimide compound and a polyamine has been developed. (For example, see JP-A-63-68637) Further, a hardened material of the heat resistant resin composition made of such a maleimide-based resin has excellent heat resistance.